MIAMI — Whatever drama may have been building between the Nets and the Miami Heat abruptly faded in the fourth quarter on Thursday night, and perhaps even died in the deep left corner at American Airlines Arena.

“It’s a two-point game with five minutes to go,” said the Nets’ Paul Pierce. “Right where we want to be.”

And then came LeBron James, driving the right baseline against an overmatched Mirza Teletovic, skipping a bounce pass along the baseline to Mario Chalmers for an open 3-pointer. Forty-five seconds later, Ray Allen hit another for Miami from the same spot when Deron Williams failed to pick up in a defensive switch.

Miami had an 8-point lead on the way to a 94-82 Game 2 victory. If there is any buzz to this Eastern Conference semifinal, with the Heat leading two games to none, it can only be heard in Brooklyn and, knowing that crowd, it’s rather faint at that.

The Nets might have gotten everyone’s attention on a night when the Heat appeared vulnerable for three and a half quarters. But when your $100-million point guard (Williams) fails to score a point and you can’t get a rebound on three successive misses by James over a 100-second span late in a still competitive game, do not expect to be taken too seriously as a threat to unseat a defending champion, much less feared.

Here in South Florida, in fact, the Nets were treated this week more like the ghost of Boston teams past, or skeletons sneaking out of James’s closet. Heat Coach Erik Spoelstra’s cracked that Paul Pierce and Kevin Garnett were still wearing green underneath their black Brooklyn uniforms. In its pre-series positional matchups, The Miami Herald twice referred to the Nets as the Celtics.

Worse, the Heat treated both games — neither of which produced their best — with a clinical dispassion, even if Dwyane Wade promised that as the series wore on, “it’s going to start feeling a little bit more like those old playoff games.”

Pat Riley always said that a playoff series cannot feel truly competitive until a home team loses. But it also has become axiomatic that you can’t microwave a rivalry based on the regular season, and the Nets’ 4-0 2013-14 whitewash of the Heat may be the most instructive example.

As they head home to a city that may already have lost interest in them, there is another dynamic the Nets must grapple with, after having been largely irrelevant competitively and commercially for most of their existence in New Jersey before their move across two rivers to Brooklyn. While that is no great distance, they have only begun building an impassioned fan base, and that has given them a diffused identity, historically speaking.

Asked if this series felt like an old rivalry because of Pierce and Kevin Garnett or a new one, Wade said: “Kind of a new one, though obviously with K. G. and Paul, we’ve played against them a lot of times in the playoffs.”

It isn’t helping that Pierce and Garnett — in juxtaposition to the Heat stars in their primes — appear to be aging 96 basketball minutes for every 48 played. In Game 2, Garnett was far more active with 12 rebounds, 3 assists and 3 steals, but only 4 points. Pierce scored 13 points but was irrelevant in the fourth quarter.

As in Game 1, the Heat had the most formidable former Celtic, as Allen, a long-range shooter nonpareil, added 13 points to the 19 he scored in Game 1. Allen’s performance here this week was a stinging alarm for the Nets. They staked so much on the acquisition of their own former Celtics that it was understandable that Miami (and its newspaper) mistook them for the Celtics.

When Miami needed a fourth-quarter lift, its Big 3 of James, Wade and Chris Bosh made all the plays that required hustle and skill. When the mystery of Teletovic, who scored 15 of his team-high 20 points in the first half, was solved by making sure he couldn’t set his feet and fire, the Nets had no one — not Joe Johnson, not Pierce and certainly not Williams — to make a stand.

For his part, Wade said the series would intensify and the teams would “get into it when we go up to Brooklyn for Game 3.” But after two wins at home, it’s hard to imagine the Heat losing sleep over playing at Barclays Center, where a few thousand fans figure to be rooting for them.

Two years ago the Heat lost Game 4 of a first-round series to the Knicks and streamers fell from the Madison Square Garden rafters. The Knicks hadn’t won a postseason game in 11 years. It was a pathetic show of desperation, but one that reflected a desire to celebrate something, anything, with a long-suffering and ever-passionate fan base.

The Nets are still feeling their way, trying to forge an identity. But rather than chide the Brooklyn fans for not being rabid enough, better to speculate on the Nets’ timetable for utter devotion: all in due time.

Or, perhaps, never, if the goal is to reach or clear the bar set by the Knicks.

All the Nets can do is grit their teeth when Miami treats them with indifference and if New York seems distracted this weekend with the N.F.L. draft or, worse, with the Knicks’ ongoing search for a coach.

In building hope, it’s all about the buzz. The Nets had a chance to bring home a deadlocked series and failed in the clutch. Going home, they are not right where they wanted to be.

A version of this article appears in print on , on Page B16 of the New York edition with the headline: Rather Than Buzz, the Nets Garner a Ho-Hum. Order Reprints | Today’s Paper | Subscribe